@article{1183419222, author = {Kasner, Edward}, title = {Systems of extremals in the calculus of variations}, journal = {Bull. Amer. Math. Soc.}, volume = {14}, number = {3}, year = {1907}, pages = { 289-292}, language = {en}, url = {http://dml.mathdoc.fr/item/1183419222} }
Kasner, Edward. Systems of extremals in the calculus of variations. Bull. Amer. Math. Soc., Tome 14 (1907) no. 3, pp. 289-292. http://gdmltest.u-ga.fr/item/1183419222/